Promising thermoelectric properties of phosphorenes

Abstract

Electronic, phononic, and thermoelectric transport properties of single layer black-and bluephosphorene structures are investigated with first-principles based ballistic electron and phonon transport calculations employing hybrid functionals. The maximum values of room temperature thermoelectric figure of merit, ZT corresponding to armchair and zigzag directions of blackphosphorene, ∼0.5 and ∼0.25, are calculated as rather smaller than those obtained with firstprinciples based semiclassical Boltzmann transport theory calculations. On the other hand, the maximum value of room temperature ZT of blue-phosphorene is predicted to be substantially high and remarkable values as high as 2.5 are obtained for elevated temperatures. Besides the fact that these figures are obtained at the ballistic limit, our findings mark the strong possibility of high thermoelectric performance of blue-phosphorene in new generation thermoelectric applications.

Green function, quasi-classical Langevin and Kubo–Greenwood methods in quantum thermal transport

“…This is of particular importance for phonons, where for a given device length different transport regimes take place at different parts of the spectrum, all of which contribute to heat current. GF method has been used for a range of systems, some of which are atomic chains [22], molecular junctions [67][68][69][70] carbon nanotubes and graphene based materials [64,[71][72][73][74][75][76][77][78][79], silicon nanowires [80][81][82], novel two-dimensional crystals [83,84]. Below we review some of these works, where the advantageous sides of the GF methodology has been useful.…”

Thermoelectric effect and devices on IVA and VA Xenes

“…ZT was predicted to be 2.5 or 0.016, based on semiclassical Boltzmann transport theory calculations or first-principles respectively. 142,143 The distinct contrast is due to large variation in estimated thermal conductivities by three orders of magnitude. To improve the thermoelectric properties, one trend involves constructing heterostructures from other allotropes of phosphorene, besides doping with Ti and forming vacancies.…”

Black Phosphorus-New Nanostructured Material for Humidity Sensors: Achievements and Limitations

“…It was established that electronic, phononic, and thermoelectric transport properties of single layer BP allow to hope for the achievement of extremely high values of thermoelectric figure of merit, ZT (the criterion for commercial deployment); ZT is proportional to the square of Seebeck coefficient, and the ratio of an electrical conductance of thermoelectric material to its thermal conductance. With a regular decrease of the lattice thermal conductivity in phosphorene compared with bulk BP, ZT can reach more than 2.5 for elevated temperatures (500 K) [65,66]. As is known, for practical applications figure of merit should be more than 1.0, and one of the approaches to increase ZT is to increase the operating temperature.…”

“…The listed set of properties of BP means that 2D black phosphorous is a promising material for the development of electronic and photoelectric sensors for various applications, including biosensors [28,29,32,67,68,69], and new generation of thermoelectric converters for energy applications [65,66]. Unlike most thermoelectric materials, whose ZT are small at low temperatures, the ZT of phosphorene is still substantial (ZT > 1), even at room temperature.…”